Ejector for power presses



March 13, 1934. E. 'w. ZEH

EJEGTOR FOR POWER- PRESSES Filed March 5, 1931 3 Sheets-Sheet l I I ATTORNEYS M rh 13, 1934. v E. w. ZEH EJEC" OR POWER 3 Sheets-Sheet 2 Filed March 5, 1931 5 z 22 cu Z I.

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l 0 ATTORNEYS E. w. ZEH 1,951,229

EJECTOR FOR POWER PRESSES Filed March 5. 1931 s Sheets-Sheet 5 1S. R w o 61-- 7 m m 6 l v i.. m A HUN. \I I III I II lql m 7 4 U a ,W 7 6 w 9 w I; lg m .w H a 5 Wm W 9% Q Q a /u HWJJ 6% WM J 4 J I 4 2 J T 1 b WW m Y 5 4 V Z 1 March 13, 1934.

Patented Mar. 13, 1934 r TE . 7 Claims.

This invention relates in general to that class of power presses in which a head for carrying one die is moved toward and away from a bed sup-'- porting a fixed die by a screw which is alternately rotated opposite directions by alternate engagement of a pair or friction disks with opposite sides of a friction wheel carried by the screw, tire invention being more particularly directed to large presses of this type utilized for operations wherein the work may become stuck upon the die carried by the head, for example, in die forg ng operations. in such presses, the return or upward movement of the head and upper die.

is not uniform; in other words, the head sometimes rnoves farther on the return movement at other times, due to the momentum of the friction wheel slight variations in the brake in; thereo One object or the invention is to provide novel and improved means for stripping or ejecting work from the fie carried by the head or" a power press, whereby quick and positive ejection of the work from the die is ensured.

another is to provide an ejector or die stripper of the general character described especially adapted for use with power presses of the particular type described, so that the ejector shall be actuated only a predetermined distance regardless of variations in the return or upward movement of the head of the press. In other words, the invention particularly contemplates a die stripper or work ejector of this character embodying novel and improved features of construction which shall compensate for non-uniforrn return movement of the head of the press.

1's further object of the invention is to provide an ejector for power presses embodying novel and improved features oi construction, whereby ejecting pressure shall be exerted upon the work uniformly at a plurality points to ensure easy and positive stripping or ejecting or" the work from the die.

Gtner objects are to provide such an ejector comprising a plurality of ejecting members or plungersniounted the head or" the presaand means for simultaneously and uniformly actuating all of aid plungers; to provide such apparatus which shall be simple, inexpensive and reliable in construction and operation; and to obtain other advantages and results as will be brought out by the following description,

Eeierring to the accompanying drawings, in corresponding and like parts are designated throughout several views by the same reference characters,

Figure 1 is a front elevation of a power press having an ejector embodying my invention, showing the parts with the dies separated and the work'being ejected;

Figure 2 is a fragmentary front elevation of the press showing the dies in engagement to op crate upon the work;

Figure 3 is a fragmentary emerged horizontal sectional view, on the line 3 3 of Figure 2;

Figure 4 is an enlarged fragmentary transverse vertical sectional view, on the of Fig ure 2;

Figure 5 is a fragmentary transverse vertical sectional view, on the line 5-5 of Figure 3, showing the dies separated and the work being ejected from the die;

Figure 6 is a view, on the line oi Figure 3, portions being broken away;

Figure 7 is a fragmentary transversevertical sectional View through the head oi the press shot-7 t" ing a modification of the invention, and

Figure 8 is a view similar to Figure 5 showing a furtner modiiication.

The invention is specifically described in con nection with a known type of screw power press which includes a frame 1 that is provided with. an elongated vertically disposed opening 2 extending transversely through the ire-me at its longitudinai center, said opening being formed at the lower end with a bed 3 upon is fined a die a. The sides of the opening 2 are provided with vertical guides 5 upon andlietween wmcn is mounted a vertically slidable head 6 upon is mounted a die holder '7 carrying a die 8 to co operate with the fixed die 4 for producing a forging A. The exact form of the dies is imma. terial to the invention, and. varies according to work to be produced, but in the present instance the die 4 has a recess 9 into which the die is is movable to compress heated metal for to the cup-shaped forging A.

The heads is carried by the lower end or a vertical screw 10 which has a suitable swivel connection with the head and extends upwardly through the top of the-trams l, the upper end thereof being provided with a horizontally disposed wheel 11 having a niction surface on its periphery. It is obvio therefore, rotation I of the screw alternately in opposite directions will cause the head to be moved up and down on the ice uides 5.

arranged alcove the friction wheel 11 and diemetrically thereor .is a horizontally i drive slistt l2 journaledin s 13 and is at the upper ends or umtanding brackets is and is no secured to opposite sides 05. the frame. The bearings 13 and. 14 are preferably antifriction, and the shaft 12 is both rotatable and slidable therein. Fixed on the shaft 12 at diametrically opposite sides of the friction wheel 11 is a pair of friction disks 1? and 18 adapted to alternately engage the friction surface of the wheel ll to rotate the screw 10. The disks have the respec 've pulleys 19 and 20, which are adapted to receive drive belts (not shown) to rotate the shaft 12. Assuming the shaft 12 to be rotating in the direction of the arrows on Figures 1 and 2, it will be obvious that as the friction disk 17 engages the wheel ll the head 6 will he forced downward- 1y, while engagement of the disk 18 with the wheel 11 will move the head 6 upwardly. To accomplish the alternate engagement of the friction disks 1'? l8 with-the friction wheel ll the shaft 12 is slidaole in its bearings, and is preferably actuated by a fluid pressure motor 21 controlled by a valve, or by other suitable means, not shown.

With this construction, it will be observed that the die forging or other worlr may he produced by cooperation of the dies l and 8 which is caused by reciprocation of theheaol 6, the work being removed from the dies when the head 6 moves on its upward or return strolre.

Frequently the work A shrinks and becomes stuck: or jannned upon the upper die 8 so that the work moves upwardly with the die and does not become released thererrom. The present inven tion. is directed toward a stripping or ejecting ap paratus to positively remove the work from the upper die This apparatus includes a plurality of knockout plungers 22 vertically slidahle in openings 23 in the head 6 and arranged transversely thereof in the same plane. These plungers 22 are simultaneously reciprocated by any suitable means, for example, as shown in Figure 5 of the drawings. by a long pinion 2 journaled to rotate about a horizontal axis in an opening 240 in the head 6 and meshing with rack teeth 25 upon each of the plungers'. The pinion 24 projects from the head 6 at the front thereof and has connected thereto-a crank arm 26 having a roller 2'? on one end. This crank arm is normally influenced by suitable means, such as a spring 28, into an approximately horizontal position, as shown in Figure 2 of the drawings, so as to move the plungers 22 upwardly in their openings 23. Movement of the crank arm in this direction is limited by a stop lug 29 which engages a boss so on the head. 6. I

Within the path of movement oi the cranlr arm 26 the head 6 moves up and down and iiitermecliate the limits of movement of said head, is an abutment track 31 secured to the frame of the press and having a horizontal portion 32 which lies in the path of movement of the roller 2? so as to be engaged momentarily thereby to oscillate the crank; arm when the head 6 is raised and lowered. The track 31 has another portion disposed substantially vertically and at an angle to the portion 32. When the head is in its lower position, as shown in Figure 2 of "he drawings, the crank arr-o 26 clears the tract. El and the roller 2'? lies under the portion 32 of the track. As the moves upwardly, the roller 27 engages the portion 32 of the track so the crank arm is rotated downwardly in the direction of the arrows shown in Figure l of the drawings, which results in the plunger-s 22 being slid downwardly in their openings 23. The roller 26 may then follow the vertical portion 33 LQELEEZQ of the track without further rotation of the crank arm, so that regardless of slight vsrlations in the extent of upward movement of the head 6, the plungers 22 will he slid downwardly only a predetermined distance. all

The plungers 22 actuate a stripper plate 34 which is mounted on rods 35 vertically slidable in the die holder 7. This stripper plate has an opening 36 to nicely slide upon the die 8 and is normally held snugly against the lower end of the die holder by compression springs 3'], so as to clear the end of the die and leave the latter free to co operate with the lower die 8, as shown in Figure 4 of the drawings. Each of the rods 35 is in slimement with and abuttingly engaged by one of the plungers 22, as clearly shown in l and 5 of the drawings.

In operation, when the dies are brought into work-forming relation, as shown in Figure 4 oi the drawings, the stripper plate is arranged hetween the dies and in tight engagement with the lower end of the die holder 7. As the head 6 moves upwardly and the roller 21? engages the track 32, the plungers 22 are forced downwardly and in turn push the rods 35 downwardly so as to slide the stringer plate downwardly upon the die 8 and force the Work A from the die, as clearly shown in Figures 5 and 6 oi the drawings.

It will he observed that the pressure is applied to the stripper plate at diametrically opposite I sides thereof so that the pressure is balanced and uniform, and the plungers 22 are simultaneously actuated, so that there is a :oositive and uniform pressure exerted on all parts of the work whereby it is easily and quickly dislodged from the upper die 8. it will also he observed that the action is like that of a hammer; in other words, when the roller 2'? strikes the track. 31, the stripper plate is quickly pushed downward.

)ther means than the rack and pinion 25 for actuating the plungers, may be utilized. For example, as shown in Figure s of the drawings, each plunger may be provided with a notch 33 engaged by the end 39 of a crank so mounted on a shaft s1 which is rotatable like the pinion Furthermore, any desired number of plungers 22 may be utilized, according to the worl: to be produced in the press, and in Figure l or the drawings I have shown three plungers.

From the foregoing, it will be understood that the stripper plate 34 is moved downwardly into die-stripping position as the head of the press moves upwardly to separate the dies, and is held in this position by the track 33 until the head next move-s downwardly, and that the string r Ego plate is ehtuated only a predetermined distanceregardless of the extent of return movement of the head 6, so that there is no possibility of damage to any of the parts by overthrow of the return movement or the head. The plurality of plungers 13g 22 provides for flexibility in the adaptation of the press to various types of work, and also en ables uniform ejecting pressure to he applied to the worlr at a plurality of points. The shape and size of the stripper plate obviously may be varied gig-n in accordance with the kind of worlr and the dies, and may he separahly connected to the rods Other modifications and changes in the details of construction of the apparatus will appear to those skilled in the art without departing from the spirit or scope of the invention, and therefore ll do not desire to be understood as limiting myself in. the construction and use of the invention except as required by the following claims; when construed in the light of the prior art.

having thus described the invention, what 1 I receive a fixed die, a head reciprocable in said iii) fe to receive a die to cooperate with said fixed die, and means for reciprocating said head to cause engagement and separation of said dies, of means for ejecting work from the die on said head including a plurality of reciprocating plungers on said head each having a rack thereon, a member to oscillate on said head, a pinion journaled in said head and. connected to said member and meshing with said racks of all of said plungers to simultaneously reciprocate said plungers upon oscillation of said member, and means for oscillating said member alternately in opposite directions upon movement of said head in opposite directions respectively. v

2. In a press, the combination with a frame to receive a fixed die, a head reciprocable in said frame to receive a die to cooperate with said fixed die, and means for reciprocating said head to cause engagement and separation of said dies, the extent of movement of said head to separate said dies being variable, of means for ejecting Work from the die on said head including a plurality of cooperating parts one of which is a knockout plunger to ejectwork from the die and the other of which is a movable member. mounted on said head to actuate said knockout member, and an abutment means including an abutment to be engaged momentarily by said movable member at a predetermined point in the .movement of said head in a direction to separate said dies and actuate said movable member a predetermined distance to move said knockout plunger a predetermined distance to eject work from said die on the head, said abutment means including a track beyond said abutment over which said movable member may idly move with said head in said direction beyond said predetermined point in the movement of the head without further actuation of said knockout plunger, wherebyexcessiveejecting movement of said knockout plunger and excessive strain on said ejecting means as a result of variations in extent of movement of said head in said direction are prevented.

3. The press set forth in claim 2, with the addition of means for returning said movable member and said knockout member to their normal positions when said movable member passes said abutment during movement of said head in the direction to cause engagement of said dies.

4. The press vset forth in claim 7 with the addition. of yielding means for normally influencing said actuating member in the direction opposite to that in which said actuating member is moved by said abutment.

' 5. In a press, the combination with a frame to receive a fixed die, a head reciprocable in said frame to receive a die to cooperate with said fixed die, and means for reciprocating said head to cause engagement and separation of said dies, the extent of movement of said head to separate said dies being variable, of means for ejecting work from the die on said head including a reciprocating knockout plunger on said head having a rack thereon, a member to oscillate on said head, a pinion iournaled on said head and connected to said member and meshing with said rack to reciprocate said plunger upon oscillation of said member, and an abutment located intermediate the limits of movement of said actuat ing member with said head to be engaged momentarily by said member as said head moves in the direction to separate said dies so as to actuate said member and move said knockout plunger a predetermined distance to eject work from said die on the head, said member being movable with said head in said direction past and out of engagement with said abutment, whereby excessive ejecting movement of said knockout plunger and excessve strain on said ejecting means as the result of variations in the extent of movement of said head are prevented.

6. The press set forth in claim 5 with the addition of yielding means normally influencing said member in the direction opposite to that in which said member is aetuated bysaid abutmerit.

7. In a press, the combination with a frame to i out plunger, an actuating member therefor movably mounted on and movable with said head and having a lateral crank arm, an operative connection between said plunger and said actuating member for actuating said plunger upon movement of said actuating member .on said head, and an abutment located intermediate the limits of movement of said actuating member with said head and at one side of the actuating member in the path of movement of said crank arm to be engaged momentarily by said crank arm of said actuating member as said head moves in the direction to separate said dies so as to actuate said actuating member "to move said knockout plunger a predetermined distance and eject work from said die on the head, said actuating member being movable with said head in said direction to move said crank arm past and out of engagement with said abutment so that further ejecting movement of said knockout plunger and excessive strain on said ejecting means during further movement of said head in said direction are prevented.

EDMUND W. ZEH. 

